The invention relates to a breath-actuated dry powder inhaler for administering dry powder medicament, or a dry powder composition of medicament mixed with a suitable carrier agent, e.g., lactose, to a patient. More particularly, the present disclosure relates to a de-agglomerator for a breath-actuated dry powder inhaler and a method of de-agglomerating a dry powder medicament or a dry powder composition of medicament and a suitable carrier.
Metered dose medicament inhalers are well known for dispensing medicament to the lungs of a patient. Some previous inhalers have comprised a pressurized aerosol dispensing container, wherein the aerosols contain gas propellants in which the powdered medicament is suspended. Upon actuation, the aerosol contents are expelled, through a metering valve, and into the lungs of the patient. However, it is now known that some aerosol propellants, including those used in metered dose inhalers, can cause depletion of the ozone layer in the atmosphere. In addition, such aerosol systems are not suitable for all patients.
Several types of non-aerosol, breath actuated dry powder inhalers have therefore been provided. For example, U.S. Pat. No. 5,503,144 to Bacon, which is assigned to the assignee of the present disclosure and incorporated herein by reference, shows a breath-actuated dry-powder inhaler. The device includes a dry powder reservoir for containing a dry powdered medicament, a metering chamber for removal of the powdered medicament from the reservoir in discrete amounts, and an air inlet for entraining the removed powdered medicament through a mouth piece upon patient inhalation.
Regardless of whether an aerosol or non-aerosol inhaler is used, it is of utmost importance that particles of the dispensed dry powder medicament be small enough to ensure the adequate penetration of the medicament into the bronchial region of a patient""s lungs during inhalation. However, because the dry powder medicament is composed of very small particles, and often provided in a composition including a carrier such as lactose, non-defined agglomerates or aggregates of the medicament form at random prior to being dispensed. It has therefore been found preferably to provide breath-actuated dry powder inhalers with means for breaking down the agglomerates of medicament or medicament and carrier before inhalation of the medicament.
Accordingly, there is desired an improved dry powder inhaler and, in particular, an improved breath-actuated dry powder inhaler. There is also desired a de-agglomerator for a breath-actuated dry powder inhaler and method for breaking down agglomerates of medicament, or medicament and carrier, before inhalation of the medicament by a patient.
The present disclosure accordingly provides a de-agglomerator for use with a breath-actuated dry powder inhaler for breaking up aggregates and micronizing particles of dry powder prior to inhalation of the powder by a patient. The de-agglomerator includes an inner wall defining a swirl chamber extending along an axis from a first end to a second end, a dry powder supply port, an inlet port, and an outlet port.
The supply port is in the first end of the swirl chamber for providing fluid communication between a dry powder delivery passageway of an inhaler and the first end of the swirl chamber. The inlet port is in the inner wall of the swirl chamber adjacent to the first end of the swirl chamber and provides fluid communication between a region exterior to the de-agglomerator and the swirl chamber. The outlet port provides fluid communication between the second end of the swirl chamber and a region exterior to the de-agglomerator.
A breath induced low pressure at the outlet port causes air flows into the swirl chamber through the dry powder supply port and the inlet port. The air flows collide with each other and with the wall of the swirl chamber prior to exiting through the outlet port, such that any powder entrained in the air flows is broken down and micronized. The de-agglomerator further includes vanes at the first end of the swirl chamber for creating additional collisions and impacts of entrained powder.
The present disclosure also provides a method of de-agglomerating dry powder from a breath-actuated dry powder inhaler, prior to inhalation of the dry powder by a patient. The method includes directing a first breath-actuated air flow for entraining a dry powder from an inhaler into a first end of a chamber extending longitudinally between the first end and a second end, the first air flow directed in a longitudinal direction.
A second breath-actuated airflow is directed in a substantially transverse direction into the first end of the chamber such that the air flows collide and substantially combine. Then, a portion of the combined air flows is deflected in a substantially longitudinal direction towards a second end of the chamber, and a remaining portion of the combined air flows is directed in a spiral path towards the second end of the chamber. All the combined air flows and any dry powder entrained therein are then delivered from the second end of the chamber to a patient""s mouth.
The de-agglomerator and method of de-agglomerating according to the present disclosure, therefore, ensure that particles of dry powder are small enough for adequate penetration of the powder into a bronchial region of a patient""s lungs during inhalation of the dry powder by the patient.
Further features and advantages of the presently disclosed de-agglomerator and method of de-agglomerating will become more readily apparent to those having ordinary skill in the art to which the present disclosure relates from the following detailed description and attached drawings.